Parkinson's disease is characterized by a progressive loss of dopamine (DA) neurons of the nigrostriatal system and by the presence of Lewy bodies (LB) and neurites (LN), proteinaceous intraneuronal inclusions mainly composed of filamentous alpha-synuclein aggregates. Alpha-synuclein is a protein which in the brain plays a central role in the control of dopaminergic neuronal functions and which is thought to be critically implicated in PD pathophysiology. Indeed, besides the fact that alpha-synuclein is the main protein component of LB, genetic studies showed that certain point mutations in and multiplications of the alpha-synuclein gene cause familial forms of PD. A large body of evidence indicates that alpha-synuclein pathology at dopaminergic synapses may underlie the onset of neuronal cell dysfunction and degeneration in the PD brain (Bellucci, A., et al., Brain Res. 1432 (2012) 95-113).
Lewy bodies, which are deposits of alpha-synuclein, are the pathological sign of Parkinson's Disease (PD) (Goedert, M., Nat. Rev. Neurosci 2 (2001) 492-501). The staging of brain pathology related to sporadic PD is reported by Braak et al. (Neurobiology of aging 24 (2003) 197-211).
Alpha-synuclein fibrillar aggregates are the main component of Lewy bodies and Lewy neurites. Recent scientific work suggests that prefibrillar oligomers of alpha-synuclein may be key contributors in the progression of Parkinson's disease (Luk, K. C., et al., Science 338 (2012) 949-953; Auluck, P. K., et al., Science 295 (2002) 865-868; Bodner, R. A., et al., Proc. Natl. Acad. Sci. USA 103 (2006) 4246-4251; Bucciantini, M., et al., J. Biol. Chem. 279 (2004) 31374-31382; El-Agnaf, O. M., et al., FASEB J. 20 (2006) 419-425; Kayed, R., et al., Science 300 (2003) 486-489; Lashuel, H. A., et al., J. Mol. Biol. 322 (2002) 1089-1102; Masliah, E., et al., Science 287 (2000) 1265-1269.).
Chai, Y-J., et al., report that the secreted oligomeric form of α-synuclein affects multiple steps of membrane trafficking (FEBS Lett. 587 (2013) 452-459). Exosomes of BV-2 cells induced by alpha-synuclein: important mediator of neurodegeneration in PD is reported by Chang, C., et al., Neurosci. Lett. 548 (2013) 190-195). Feng, R. L., et al. report that alpha-synuclein mediates alterations in membrane conductance: a potential role for alpha-synuclein oligomers in cell vulnerability (Eur. J. Neurosci. 32 (2010) 10-17). Lee, H-J., et al. report that autophagic failure promotes the exocytosis and intercellular transfer of alpha-synuclein (Exp. Mol. Med. 45 (2013) e22). The synaptic pathology of alpha-synuclein aggregation in dementia with Lewy bodies, Parkinson's Disease and Parkinson's Disease Dementia is reported by Schulz-Schaeffer, W. J. (Acta Neuropathol. 120 (2010) 131-143).
The vast majority of alpha-synuclein in human brain is N-terminally acetylated (Kellie, J. F., et al., Sci. Rep. 4 (2014) 5797) and this N-terminal acetylation inhibits alpha-synuclein from aggregation (Bartels, T., et al., PLoS One 9 (2014) e103727).
Different oligomeric forms of recombinant alpha-synuclein have been reported: type A oligomers (cytotoxic, effect on Ca2+ influx), type C oligomers (aggregate seeding species), fibrils mixed with lipids (seed the aggregation of intracellular aggregates), triple proline (TP) mutant A30P/A56P/A76P (forms predominantly toxic oligomers) (see e.g. Danzer, K. M., et al., J. Neurosci. 27 (2007) 9220-9232; Danzer, K. M., et al. J. Neurochem. 111 (2009) 192-203; Luk, C. K., et al. Proc. Natl. Acad. Sci. USA 106 (2009) 20051-20056; Desplates, P., et al. Proc. Natl. Acad. Sci. USA 106 (2009) 13010-13015; Karpinar, D. P., et al., EMBO J. 28 (2009) 3256-3268; Lee, H-J., et al., J. Biol. Chem. 285 (2010) 9262-9272; Hansen, C., et al., J. Clin. Invest. 121 (2011) 715-725).
Pathological alpha-synuclein transmission initiates Parkinson-like neurodegeneration in non-transgenic mice is reported by Luk, K. C., et al. (Science 338 (2012) 949-953). The seeding induced by alpha-synuclein oligomers provides evidence for spreading of alpha-synuclein pathology and the exosomal cell-to-cell transmission of alpha synuclein oligomers is reported by Danzer, K. M., et al. (J. Neurochem. 111 (2009) 192-203; Mol. Neurodegen. 7 (2012) 42). Braidy et al. report alpha-synuclein transmission and mitochondrial toxicity in primary human foetal enteric neurons in vitro (Neurotox. Res. (2013) epub on Oct. 5, 2013). Desplats, P., et al. report inclusion formation and neuronal cell death through neuron-to-neuron transmission of alpha-synuclein (Proc. Natl. Acad. Sci. USA 106 (2009) 13010-13015). Direct transfer of alpha-synuclein from neuron to astroglia causes inflammatory responses in synucleinopathies is reported by Lee et al. (J. Biol. Chem. 285 (2010) 9262-9272). Lee, S-J., et al. report the cell-to-cell transmission of alpha-synuclein aggregates (Meth. Mol. Biol. 849 (2012) 347-359; Nat. Rev. Neurol. 6 (2010) 702-706). The probably strongest evidence of a progression of alpha-synuclein pathology by a possible transmission of an alpha-synuclein aggregation seed comes from postmortem analysis of brains of certain PD patients who presented with Lewy pathology in fetal neurons which were grafted to their brain 11-16 years earlier (Li, J-Y., et al., Nat. Med. 14 (2008) 501-503).
Aggregated alpha-synuclein mediates dopaminergic neurotoxicity in vivo (Periquet, M., et al., J. Neurosci. 27 (2007) 3338-3346). Pieri, L., et al. report that fibrillar alpha-synuclein and huntingtin exon 1 assemblies are toxic to the cells (Biophys. J. 102 (2012) 2894-2905). Van Rooijen et al. report that membrane permeabilization by oligomeric alpha-synuclein: in search of the mechanism (PLoS One 5 (2010) e14292).
Very recently, Wagner et al. demonstrated in cellular assays and in an alpha-synuclein transgenic mouse model that the small molecule Anle138b acts as a protective alpha-synuclein oligomer modulator which may be useful for disease-modifying therapy of Parkinson's disease (Wagner, J, et al., Acta Neuropathol. 125 (2013) 795-813). Lynch, S. M., et al. report that a scFv intrabody against the non-amyloid component of alpha-synuclein reduces intracellular aggregation and toxicity (J. Mol. Biol. 377 (2008) 136-147). A strategy for designing inhibitors of alpha-synuclein aggregation and toxicity as a novel treatment for Parkinson's Disease and related disorders is reported by El-Agnaf, O. M., et al. (FASEB J. (2004)). Emadi, S., et al. report inhibiting aggregation of alpha-synuclein with human single chain antibody fragments and the isolation of a human single chain antibody fragment against oligomeric alpha-synuclein that inhibits aggregation and prevents alpha-synuclein-induced toxicity (Biochem. 43 (2004) 2871-2878; J. Mol. Biol. 368 (2007) 1132-1144). Smith et al. report effects of intravenous immunoglobulin on alpha-synuclein aggregation and neurotoxicity (Int. Immunopharmacol. 14 (2012) 550-557). Targeting intracellular and extracellular alpha-synuclein as a therapeutic strategy in Parkinson's Disease and other synucleinopathies is reported by Vekrelis, K. and Stefanis, L. (Expert. Opin. Ther. Targets 16 (2012) 421-432).
Antibody-aided clearance of cerebral synucleinopathy in respective transgenic mice was demonstrated in an active (Masliah, E., et al., Neuron 46 (2005) 857-868) and a passive (Masliah, E., et al., PLoS One 6 (2011) e19338) immunization paradigm. Binding of extracellular alpha-synuclein by specific antibodies prevents cell-to-cell aggregate transmission was reported by Bae, E-J., et al. (J. Neurosci. 32 (2012) 13454-13469).
The use of mimotopes of alpha-synuclein epitopes for treating Lewy body diseases is reported in WO 2011/020133. In WO 2007/011907 alpha-synuclein antibodies and methods related thereto are reported. Fusion to a highly charged proteasomal retargeting sequence increases soluble cytoplasmic expression and efficacy of diverse anti-synuclein intrabodies is reported by Joshi et al. (MABS 4 (2012) 686-693). Emadi et al. (J. Mol. Biol. 368 (2007) 1132-1144) report the isolation of a human single chain antibody fragment against oligomeric alpha-synuclein that inhibits aggregation and prevents alpha-synuclein-induced toxicity. The detection of morphologically distinct oligomeric forms of alpha-synuclein is reported by Emadi et al. (J. Biol. Chem. 284 (2009) 11048-11058). Zhou et al. (Mol. Ther. 10 (2004) 1023-1031) report that a human single-chain Fv intrabody blocks aberrant cellular effects of overexpressed alpha-synuclein. That antibodies against alpha-synuclein reduce oligomerization in living cells is reported by Nasstrom et al. (PLoS One 6 (2011) e27230). Protofibril-binding antibodies and their use in therapeutic and diagnostic methods for Parkinson's Disease, dementia with Lewy bodies and other alpha-synucleinopathies are reported in WO 2011/104696. Isolating recombinant antibodies against specific protein morphologies using atomic force microscopy and phage display technologies is reported by Barkhordarian et al. (Prot. Eng. Des. Select. 19 (2006) 497-502). Kvam et al. (PLoS One 4 (2009) e5727) report that conformational targeting of fibrillar polyglutamine proteins in live cells escalates aggregation and cytotoxicity.